Reading on in the thread it seems that there's agreement on using "static" instead of "const", to s/const/static :-)
M.-A. Lemburg wrote: > Georg Brandl wrote: >> M.-A. Lemburg wrote: >> >>> A nice side-effect would be that could easily use the >>> same approach to replace the often used default-argument-hack, >>> e.g. >>> >>> def fraction(x, int=int, float=float): >>> return float(x) - int(x) >>> >>> This would then read: >>> >>> def fraction(x): >>> const int, float >>> return float(x) - int(x) >> There's a certain risk that the premature-optimization fraction will >> plaster every function with const declarations, but they write >> unreadable code anyway ;) >> >> Aside from this, there's still another point: assume you have quite a >> number of module-level string "constants" which you want to use in a switch. >> You'd have to repeat all of their names in a "const" declaration in order >> to use them this way. > > If you want to use the switch-dispatch table optimization, yes. > > I'm sure we could find ways to make such declarations more > user-friendly. E.g. to declare all symbols imported from a > module constant: > > # Declare the name "module" constant: > const module > > # Declare all references "module.<something>" constant: > const module.* > > This would allow you to e.g. declare all builtins constant, > avoiding cluttering up your code with const declarations, > as in the above example. > > Note that such a declaration would go beyond just the use in > a switch statement. It allows you to declare names reserved > within the scope you are defining them in and gives them > a special meaning - much like "global" does. > > Indeed, with this kind of declaration you wouldn't need to > add the switch statement to benefit from the dispatch > table optimization, since the compiler could easily identify > an if-elif-else chain as being optimizable even if it uses > symbols instead of literals for the values. > > Furthermore, the compiler could do other optimizations on the > const declared names, such as optimizing away global lookups > and turning them into code object constants lookups. > -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Jun 23 2006) >>> Python/Zope Consulting and Support ... http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ ::: Try mxODBC.Zope.DA for Windows,Linux,Solaris,FreeBSD for free ! :::: _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
